Adult-type carcinomas in children: Their characteristics and differences from adult-onset carcinomas

Abstract

Various cancers develop during childhood, and hematological malignancies, brain tumors, malignant bone tumors, and soft tissue sarcomas are common. Malignant epithelial neoplasms (adult-type carcinomas) are most common during adulthood and extremely rare in childhood. However, some adult-type carcinomas can occur during childhood. This study included patients aged < 15 years with adult-type carcinomas. We identified papillary thyroid carcinoma, medullary thyroid carcinoma, adrenocortical carcinoma, colorectal carcinoma, fibrolamellar variant of hepatocellular carcinoma (FLHCC), pancreatic acinar cell carcinoma, and mucoepidermoid carcinoma of the lungs. Medullary thyroid carcinoma was detected during surveillance for multiple endocrine neoplasia type 2. Li-Fraumeni syndrome manifests with the development of adrenocortical carcinoma. A case of colorectal carcinoma was detected during surveillance for constitutional mismatch repair deficiency syndrome. Children may develop tumors with the same histology as adults. However, the background of such tumors is often different from that of adults; for instance, in relation to hereditary tumors. Notably, several rare adult-type carcinomas, including FLHCC, acinar cell carcinoma, and mucoepidermoid carcinoma, are more common in children. This article presents actual cases of adult-type carcinomas in children and outlines their characteristics and differences from adult-onset carcinomas.